as an aside Burqaposh, why are Yemen, Saudi Arabia etc the heartlands of Muslims for you?
Very good question.
Heartland is just that, the region (or land) that acts as heart, that drives the emotions, the trends etc.
For many Sunni Muslims (and that's majority), the heartland regions are the epitome of Islam and the true Islamic thought. Many strict Muslims want to walk, talk, dress, and above all THINK like the people from heartland.
A Pakistani may not have ever experienced the heartland culture, but you will so many so called strict-Muslims trying to ape the tribals using things like hijab. Even though Pakistani culture never had that kind of dress code.
You can also do a test and see how many British-born Pakistanis are driven by the Islamic thought emanating from the heartland, and not from the thoughts of British Institutions like their universities or British parliament.
Look at Swatis, what they are doing with hand chopping, neck cutting etc is the ditto copy of what is practiced by the tribals of the "heartland" of Muslims. This type of caveman behavior was never a local custom not at least in the recent memory.
Shias too have a heartland, and that is Iran. Whatever you say, Iran can never be wrong for a typical Shia. However Iranian heartland has much less influence and that influence extends to Shia population centers in South Asia and tiny portions of the Middle East such as Lebanon.
So I hope I have answered your question.
p.s. It is unfortunate to say that even Ahmadis of today do not possess INDEPENDENT thinking. And they have become a copy of the tribal practices of Sunnis and Shias.